Wharton professor Jeremy Siegel points to disappointing productivity growth as a key reason many Americans are dissatisfied with the economy, as wage increases struggle to keep up with inflation.

Speaking on CNBC's "Squawk Box," Siegel stated, "Productivity growth over the last three quarters has been very poor, and we need to boost that metric." He added that the current pace is below the 15-year average, noting that "workers' incomes are being eroded by inflation."

Siegel highlighted that since the launch of generative pre-trained transformer (GPT) models in late 2022, productivity has grown at an average annual rate of about 2.5%, but has recently weakened. He believes a rebound in productivity could lift real wages and provide support for the broader economy.